Mara said the Giants view Herzlich as a “prospect.” Herzlich was among the best linebackers in college football in 2008 before he was diagnosed with Ewing’s sarcoma, a rare bone cancer, in his left leg. He returned to football last season, but went undrafted in April.

“He’s a great kid and he’s certainly had his share of obstacles to overcome and we’re excited to give him the opportunity,” Mara said.

Herzlich, who was invited to April’s draft, ranked among the top undrafted players available. He was seemingly in demand, and wrote on his Twitter page on Monday that he would make his final decision yesterday. He picked the Giants, who still could use help at the position despite drafting two linebackers over Herzlich in April.

“They’re a team that needs linebackers, it’s a great opportunity for me to get in and play and be on a team,” Herzlich said during an interview with ESPN. “And it’s a great community feel. It’s a family-owned team, I know the Maras, I know (Tom) Coughlin from Boston College. It just seemed like a great place to be.”

Today was the first day teams could sign undrafted free agents. The Giants agreed to terms with Florida defensive end and Don Bosco Prep alum Justin Trattou, Pitt fullback Henry Hynoski and Richmond defensive tackle Martin Parker, all according to people with knowledge of the pending transactions but who requested anonymity because the deals are not yet signed and official.

Iowa State defensive tackle David Sims also wrote on his Twitter page that he’s going to play for the Giants.